1. Field of the Invention
The present invention is related to a liquid crystal display device and related alignment method, and more particularly, to a liquid crystal display device and related alignment method with ESD protection and reduced mura.
2. Description of the Prior Art
With rapid development of large-size liquid crystal display (LCD) panels, the ability to provide multi-viewing angles have become a major feature. Because of the advantages of multi-viewing angles and low response time, multi-domain vertical alignment (MVA) LCD panels have become the mainstream products of the large-size display panels.
Conventional MVA LCD panels provide multi-viewing angle function by making the liquid crystal molecules in different areas slant in different directions using protrusions (bumps). However, in addition to complicating manufacturing processes, protrusions may also block part of light, thereby lowering the aperture ratio and the brightness performance.
Therefore, polymer stabilized alignment or phase separation alignment (PSA) technology has been developed in which polymers are used to replace the protrusions in MVA LCD panels. The core of PSA technology is to forma polymer-alignment layer over a conventionally coated polyimide by mixing a UV-curable monomer into the liquid crystal molecules. The monomer is then activated by UV radiation while applying a curing voltage. The monomer reacts with the polymer layer to form a surface that fixes the pre-tilt angle of the liquid crystal molecules.
FIG. 1 is a diagram illustrating a prior art LCD device 600. The LCD device 600 includes an LCD panel, a gate driving circuit, a source driving/testing circuit, a multiplexer, and an alignment circuit. The LCD panel is manufactured using PSA technology in which a plurality of data lines, a plurality of gate lines, and a plurality of pixels (not shown) are disposed. The gate driving circuit may provide gate driving signals for turning on each column of pixels. The source driving/testing circuit may provide data signal DIN for charging corresponding rows of pixel. According to the data signal DIN and switch control signals SW1˜SWM, the multiplexer may output data signal DOUT1˜DOUTM to the LCD panel.
During the alignment period, the multiplexer in the prior art LCD device is floating. Unstable curing voltage or electrostatic discharge (ESD) may influence the alignment process and cause image mura which downgrades display quality.